Sea-lord arranging trials (7)
I believe the answer is:
ordeals
'trials' is the definition.
(I know this)
'sea-lord arranging' is the wordplay.
'arranging' indicates anagramming the letters.
'sea'+'lord'='sealord'
'sealord' is an anagram of 'ORDEALS'.
(Other definitions for ordeals that I've seen before include "Trying experiences" , "Tribulations" , "Difficult experiences, hard times" , "difficult tests" , "Testing experiences" .)